Abstract: The invention relates to a method for producing an aerogel using a sol-gel process, in which first a lyogel is formed from at least two precursor sols and the lyogel is then converted to an aerogel.

Abstract: The invention relates to a method for producing an aerogel under increased pressure, to the aerogel obtained using said method and to their use.

Abstract: The invention relates to a method for hydrophobising leather, comprising the steps: providing tanned, at least partly dried leather whose content of free water is in the range of from 0 to 25 wt. %, based on the weight of the dried leather, treating the leather with a mixture of compressed gas and a hydrophobising agent at a pressure of at least 30 bar in a pressure vessel, and relieving the pressure of the pressure vessel to ambient pressure. By using the method according to the invention it is possible to obtain leather which is hydrophobised at the surface, as well as thick and firm, deeply hydrophobised leather, as is used, for example, for shoe soles.

Abstract: The invention relates to a method for hydrophobising leather, comprising the steps: providing tanned, at least partly dried leather whose content of free water is in the range of from 0 to 25 wt. %, based on the weight of the dried leather, treating the leather with a mixture of compressed gas and a hydrophobising agent at a pressure of at least 30 bar in a pressure vessel, and relieving the pressure of the pressure vessel to ambient pressure. By using the method according to the invention it is possible to obtain leather which is hydrophobised at the surface, as well as thick and firm, deeply hydrophobised leather, as is used, for example, for shoe soles.

Abstract: The present invention relates to a process for tanning animal hides which comprises the steps of: bating and pickling the animal hide in aqueous solution, reducing the liquid content of the animal hide, replacing at least some of the liquid removed from the animal hide in the preceding step by a tanning solution which contains the tanning agent to be imbibed by the animal hide in an amount not exceeding an excess of 80%, and treating the animal hide containing the tanning solution with compressed gas in a pressurized container for a period of at least 15 minutes. Such a process is substantially wastewaterless, optionally even completely wastewaterless, and delivers high-quality through-tanned leathers or furs after short treatment times.

Abstract: The present invention relates to a method for producing fatty acid esters from fats and/or oils of biogenic origin by transesterification with monovalent or polyvalent alcohols in the presence of a special hydroxy-functional quaternary ammonium compound as the catalyst.

Abstract: The present invention relates to a process for tanning animal hides which comprises the steps of: bating and pickling the animal hide in aqueous solution, reducing the liquid content of the animal hide, replacing at least some of the liquid removed from the animal hide in the preceding step by a tanning solution which contains the tanning agent to be imbibed by the animal hide in an amount not exceeding an excess of 80%, and treating the animal hide containing the tanning solution with compressed gas in a pressurized container for a period of at least 15 minutes. Such a process is substantially wastewaterless, optionally even completely wastewaterless, and delivers high-quality through-tanned leathers or furs after short treatment times.

Abstract: The present invention relates to a method for producing fatty acid esters from fats and/or oils of biogenic origin by transesterification with monovalent or polyvalent alcohols in the presence of a special hydroxy-functional quaternary ammonium compound as the catalyst.

Abstract: The invention relates to a process for the preparation of fatty acid esters from fats and oils of biological origin by transesterification with monohydric alcohols in the presence of basic catalysts, the catalysts being salts of a basic organic compound and carbonic acid.

Abstract: The invention relates to a process for the preparation of fatty acid esters from fats and oils of biological origin by transesterification with monohydric alcohols in the presence of basic catalysts, the catalysts being salts of a basic organic compound and carbonic acid.

Abstract: The present invention relates to a process for obtaining fatty acid esters from triglycerides by means of alcoholysis. In particular, the invention relates to a process for the transesterification of fat and/or oil by alcoholysis wherein, in order to accelerate the process in the initial stage, at least one alkanol fatty acid ester is added in a quantity such that the reaction mixture produced thereby consists of one phase. A high reaction rate can thereby be maintained in the process from the beginning.

Abstract: A process for preparing fat and/or oil with a modified distribution of fatty acids in the glycerides by heterogeneously catalysed transesterification, wherein the process comprises reaction of the fat and/or oil of biological origin to be transesterified in the presence of a catalyst consisting of a metal salt of a basic amino acid or an amino acid derivative. The disadvantages of conventional transesterification processes can be overcome by using this catalyst.

Abstract: The invention relates to a method of preparation for polymers, particularly binders for powder coatings and powder coatings which are prepared as a solution in a supercritical fluid phase. Binders for powder coatings are prepared from at least two ethylenically unsaturated monomers capable of free-radical or ionic copolymerization, and conventional initiators and regulators in supercritical fluids, whereby polymerization is carried out in the homogeneous phase, and, after the reaction has ended, either the composition or the phase parameters of the mixture are altered so that at least two phases with supercritical fluid are obtained, and the phase containing predominantly polymer is separated and the polymer is separated as a powder from the sc fluid by depressurization or the polymer phase is further processed under supercritical phase conditions to the powder coating.

Abstract: This invention relates to a process for obtaining fatty acid esters from triacylglycerides by means of alcoholysis. In particular, the invention relates to a process for the transesterification of fat and/or oil by alcoholysis wherein, in order to accelerate the process, in the initial stage at least one alkanol fatty acid ester is added in a quantity such that the reaction mixture produced thereby consists of one phase. A high reaction rate can thereby be maintained in the process from the beginning.

Abstract: A method for removing free fatty acids from fats or oils of biological origin or their steam distillates by extracting the free fatty acids with a mixture of basic organic nitrogen compounds and water as an extraction medium at a temperature below the boiling point of the organic nitrogen compounds. The content of the basic organic nitrogen compounds in the extraction medium is 20-30% by weight. In this manner, the formation of a viscous soapstock which is difficult to remove is prevented. The boiling point of the basic organic nitrogen compounds used is the same as or above boiling point of water and below the boiling point of the fatty acids to be extracted in order to enable simple recovery of the extraction medium.

Abstract: In a process for producing a pulverulent product from a liquid substance or mixture of substances, the liquid substance or mixture of substances to be pulverized is first provided in a pressure vessel. A gas is then dissolved under elevated pressure in the liquid substance or mixture of substances. The resulting liquid/gas solution is then conducted out of the pressure vessel and to an expansion element, through which it is passed and rapidly expanded. Upstream of the expansion element, in the expansion element or downstream, in particular just downstream, of the expansion element, a solid pulverulent auxiliary is admixed. In this manner, a stable pulverulent product results from the solution or from the substance or mixture of substances.

Abstract: To remove free fatty acids from fats or oils of biological origin or their steam distillates, it is proposed to extract the free fatty acids with a mixture of basic organic nitrogen compounds and water as extraction medium at a temperature below the boiling point of the organic nitrogen compounds. The content of the basic organic nitrogen compounds in the extraction medium shall be at least about 20% by weight and at most about 60% by weight, preferably between about 30% by weight and about 40% by weight. In this manner, the formation of a viscous soapstock which is difficult to remove is prevented. The boiling point of the basic organic nitrogen compound(s) used shall be the same as or above the boiling point of water and below the boiling point of the fatty acids to be extracted in order to enable simple recovery of the extraction medium.

Abstract: A process for producing pulverous, i.e., powdered, preparations from sparingly soluble solid materials is disclosed. The process utilizes dimethyl ether under conditions of elevated temperature and pressure to dissolve the solid material. Upon release of the pressure, the solid material precipitates as a fine powder and the gaseous dimethyl ether is released or drawn off.

Abstract: A process is described for extracting carotenes from carotene-containing materials, in particular from fats and oils of biological origin, which provides for extraction of carotene-containing material with an extractant comprising at least one member selected from the group consisting of acetonitrile, N-methylpyrrolidone, N,Ndimethylformamide, N,N-dimethylacetamide, 4-formylmorpholine, 4-acetylmorpholine, 4-methylmorpholine, 4-phenylmorpholine.

Abstract: The invention relates to a method of preparation for polymers, particularly binders for powder coatings and powder coatings which are prepared as a solution in a supercritical fluid phase. Binders for powder coatings are prepared from at least two ethylenically unsaturated monomers capable of free-radical or ionic copolymerization, and conventional initiators and regulators in supercritical fluids, whereby polymerization is carried out in the homogeneous phase, and, after the reaction has ended, either the composition or the phase parameters of the mixture are altered so that at least two phases with supercritical fluid are obtained, and the phase containing predominantly polymer is separated and the polymer is separated as a powder from the sc fluid by depressurization or the polymer phase is further processed under supercritical phase conditions to the powder coating.